The City of Portland has been looking to understand the mobility profiles and the associated carbon impacts of different communities in the region. In addition, the City is evaluating its electric vehicle strategy, including placement of charging infrastructure based on locations that will have the greatest impact on reducing carbon emissions and encouraging use of electric vehicles (EVs). To help in this effort, researchers explored the following questions:

1) How are carbon impacts from the use of personal vehicles distributed among different neighborhoods in Portland and the Metro region?
2) Do low-income and minority communities have a greater contribution to carbon emissions than the rest of Portland?
3) What is the potential for different policy interventions to address carbon emissions from the transportation sector?

There is a consensus within the scientific community that the burning of fossil fuels has increased the amount of greenhouse gasses such as carbon dioxide (CO2) that are released into the atmosphere and is the primary cause of global climate change. Portland has been a leader amongst municipalities in addressing what will likely remain one of the biggest challenges facing humanity throughout the 21st Century. Despite being the first city in the United States to enact a local plan of action for reducing carbon emissions, the air quality in Portland remains relatively poor, earning grades of “C” and “D” for high ozone days and 24-hour particulate pollution, respectively, and ranking as the 32nd worst metro area for particulate spikes. The City of Portland is developing efforts to stay on track to meet the Climate Action Plan’s goal of an 80 percent reduction in carbon emissions below 1990 levels by 2050. At the same time, Portland recognizes the importance of making sure policies to meet environmental goals also consider equity impacts. The Portland Climate Action Plan states that currently “the many economic and health benefits of carbon reduction investments are not shared equitably across the city."

The transportation sector is responsible for 25 percent of greenhouse gas emissions in the Portland metropolitan region, 14 percent of which is comprised of emissions from cars and light trucks. For Multnomah County, the transportation sector makes up 44 percent of greenhouse gas emissions based on the city and county’s use of the ClearPath ICLEI Tool. Electric vehicles (EVs) and hybrid electric vehicle (HEVs), which are often considerably more efficient than internal combustion engine (ICE) vehicles, may have the potential to reduce the carbon footprint of automobile travel. Vehicle manufacturers are slowly but steadily rolling out new electric models. At the same time, Portland is struggling to determine where to prioritize the installation of EV charging infrastructure, a critical link to widespread adoption of EVs. Owners of EVs and HEVs, like most early adopters of new technologies, are largely high-income earners (6). Many EVs and HEVs carry a price premium over comparable ICE vehicles powered by fossil fuels and likely are not often within reach of most low-income consumers. Thus, the direct benefits of these technological advances are likely to accrue to these disadvantaged populations much later in the technological diffusion cycle, if at all. 

The question for policy makers is: are these two ends - mitigation of climate impacts from transportation sources and promoting equitable access to efficient and clean mobility - at odds with one another or can both of these goals be achieved through one coordinated strategy? This research shows with targeted investments in underserved and income communities in Portland to increase the number of alternative vehicles, you can achieve these goals.